The real estate market in Croatia has been on a hot streak lately.  Over the past few years, property values have been climbing thanks to Croatia's popularity as a tourist destination and EU membership drawing more people to live here.  The influx of demand without a matching supply of new housing has created an inventory pinch, putting upward pressure on prices. 

If you're hoping to get more bang for your buck, consider looking at rentals in smaller towns or villages or in continental part of the country (Pannonian Croatia) instead of along the coast or in the capital city.  For instance, you can likely find a fully furnished apartment for €400 or less per month in cities like Osijek.  Of course, it depends on your needs and priorities whether something further from the action makes sense.  but for the budget-conscious, broadening your search beyond the hot coastal markets could pay off.